Brake



March 8, 1938. H. w. 'GOULDTHORPE 2,110,663

. BRAKE Filed June 7, 1935 s Figll.

Inventor.'

,. Hubrt wciwldthor e, y m2 Att Patented Mar. 8, 1938 PATENT OFFICE BRAKE Hubert W. Gouldthorpe, Wesleyville, Pa., assignor to General Electric Company, a corporation of New York Application June 7, 1935, Serial No. 25,403

14 Claims.

My invention relates vto brakes.

In constructing brakes, such as electrical brakes, various schemes 'have been devised for dissipating the heat generated in the wheel or rotor thereof during braking, generally involving ventilation in which air is forced through passageways formed in the wheel. Although such provisions for cooling are generally adequate, during periods of extreme braking excessive heat may be generated. 'Ihis excessive heating may distort the wheel and produce harmful stresses if no provision is made for free movement of the braking surface relative to its hub, to permit their accommodation to expansions and contrac- 1 5 tions resulting from these temperature variations.

An object of my invention is to provide an y improved electrical brake.

Another object of my invention is to provide an improved brake wheel wherein the heat, due

to braking, is eifectively dissipated and in which the Wheel of the brake is rigid, both torsionally and axially, without being `subject to injurious stresses or strains under varying temperature conditions.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty Which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference is made to the accompanying drawing, wherein Fig. 1 is a side elevation, in partial section, illustrating an electrical brake embodying my invention; Fig. 2 is an end view taken along the line 2-2 of Fig. 1, with the stationary field structure of the brake partly broken away to better illustrate the construction; Fig. 3 is a sectionalside elevation illustrating a modification of my improvedxbrake wheel; and Fig. 4 is a fragmentary end elevation, partly in section, of the 4construction shown in Fig. '3.

Referring toFigs. 1 and 2 of the drawing, I

have shown an electrical brake embodying my invention in connection with an electric motor I0 provided with a shaft I I connected to a driven shaft I2 by a coupling I3 and supported in a bearing I4 mounted in the motor end head I5. The braking torque is produced by eddy-currents induced in two electrically conductive annular members I6 and I1 adapted to rotate in a stationary magnetic field produced by field exciting windings I8 and I9 of a stationary field structure.

The stationary field structure includes a number of iield poles 20 and 2| extending axially of (Cl. 18S-104) the rotor and arranged in two sets about the axis of the motor and supported on the motor end head I5. 'Ihe poles 2| of one set are secured by screws 22 tothe end head I5 and are equally spaced from the axis of the motor. The poles 5 20 are in axial alignment with the poles 2l and the faces of the poles 20 and 2I are spaced apart. The faces of each set of poles are arranged in substantially the same transverse plane. The set of poles 20 are secured by screws 23 to a 10 transverse plate 24 having an opening therein coaxial with the motor shaft and secured to the end head I5 by a cylindrical frame 25. These sets of field poles are excited by the field exciting windings I8 and I9, which may be electrically energized in any suitable manner, and the pairs of coaxial poles 20 and 2l are preferably excited so as to be of opposite polarity.

A braking torque is exerted on the motor shaft II and the driven shaft I2 by a rotor or brake 20 Wheel having two electrically conductive annular members or disks I6 and I1 in which eddycurrents are generated by rotation in the magnetic iields set up in the poles 20 and 2|. These disks are rigidly joined together and spaced apart 25 by spokes 26 welded to the disks, and the spokes are arranged in symmetrical, circumferentially spaced relation. This provides a brake wheel having an annular rim, which is substantially an impeller type fan with a number of radial ventl- 30 lating passages 21 intermediate the sides of the rim with openings at each end thereof and communicating with the'outer peripheral surface of the annular rim member formed by the disks I6 and I'I. The spokes 26, which are located in 35 these radial passages, form radial impeller blades and fins in good thermal contact with the disks I6 and I1, in which the heat, due to the eddycurrents, is generated. Adequate circulation of cooling air is obtained by mounting the rotor 40 in a radially spaced relation upon a hub, thereby forming axial Ventilating passages 28 communieating with the radial brake wheel Ventilating passages 21 intermediate the ends thereof, as shown in Fig. 1, through which air is blown by 45 the spokes 26 upon rotation of the -Wheel.

The hub is a fabricated unit mounted upon the motor drive shaft II formed of two parts 29 and 30 welded together. One of these parts is a disk 29, which is rigidly mounted on the 50 motor shaft, and which is slotted to -form guides 3l for the spokes 26. The other part of the hub is a cylinder 30 secured to the dis/k 29 and extending axially of the motor shaft through the opening in the transverse plate 24. A brake drum 55 is mounted on the cylindrical portion oi the hule so that the eddy-current braise can ice supplemented by a mechanical brake engaging the drum in this embodiment ci my invention, the guides 3i provide a sliding connection between the spokes and the hub and retain therotor coaxial with the motor shaft il and in a radially freely expansib-le relation upon the hub permitting its accommodation to expansions and contractions produced py temperature vari- .ations resulting from heating during braking.

, surface of the annular rim tl. rFhis rotor is maintained in a radially freely 'eipansible and spaced relation upon a hub di? coaxial therewith by cylindrical spokes 33 inserted through. the passages 35, which are interposed between pairs oi' the passages 3d. These spokes 3d are slidably fitted in the passages 35 and extend into corresponding holes in the hub iii to which they are secured by welding,as indicated at 3d. The huh 3l is adapted to be mounted on the motor shaft I I in the construction shown in Figs. 1 and 2.

As can be readily seen, this simplified construction provides a brake wheel structure which is torsionally and axially'rigid, and wherein the members, subject' to temperature Variations due to heating during braking, are relatively free to move with respect to each other. The brake wheel is essentially an impeller type fan and provides an emcient cooling arrangement wherein the air is blown though axial passages di communicating intermediate the ends thereof with the radial rotor Ventilating passages 3d.

Modications of the embodiments of my invention, which I have illustrated and described, will occur to those skilled in the art. I desire it to be understood, therefore, that my invention is not to be limited to the particular arrangements disclosed and I intend, in the appended claims, to coverall modifications which do not depart from the spirit and scope of my invention.

What I claim as newA and desire to secure by Letters Patent of the United States, is:

l. An electrical brake including an inductio rotor having an annular member with radially outwardly extending ventilating passages intermediate the sides of said annular member with openings at each end thereof, a hub, means for mounting said rotor in radially freely expansible relation on said' hub, said mounting means supporting said rotor upon said. hub in a radially spaced relation thereto to form axial Ventilating passages communicating intermediate the ends thereof with said outwardly extending passages, and means including eld exciting windings for exerting a braking torque on said rotor.

2.. An electrical brake having a field structure, means including a plurality-of crcumferentially spaced iield exciting windings for producing a iiux in said eld structure, a hub, a rotor having an annular eddy-current member adapted to rotate adjacent and in inductive relation with said eld structure, said rotor having outwardly exatrasos tending Ventilating passages formed therein intermediate the sidesof said annular member, with openings at each end thereof and having axial Ventilating passages communicating intermediate the ends thereof with said outwardly extending passages, and means for mounting said rotor concentrically on said hub and freely expansible radially with respect thereto.

3. An electrical brake including a field structure having field exciting windings, a hub having circumerentially spaced openings therein, a rotor associated with said field structure and including a pair of electrically conductive annular members axially spaced apart, and means including spokes joining said annular members together and arranged in the openings in said hub for supporting said annular members in a radially spaced relation on said hub and freely expansible radially with respect thereto.

d. An electrical brake including a iield structure having a eld exciting winding, a shaft, a hub mounted on said shaft and comprising a slotted dish and a cylindrical axially extending member, a rotor associated with said field structure and including a pair of electrically conductive annular members axially spaced apart, and means including spokes in thermally conductive relation with said annular members and mounted on said slotted disk for supporting said annular members in a radially spaced relation on said hub and freely expansible radially with respect thereto. b

5. An electrical brake including a iield structure having a field exciting winding, a shaft, a hub mounted on said shaft, said hub comprising a disk. and a cylindrical member connected together and arranged to form guides, a rotor associated with said field structure and including a pair of electrically conductive annular members axially spaced apart, and means including spolres joining said annular members together and arranged in said guides for supporting said annular members on said hub in radially spaced relation thereto.

6. An electrical brake including a held structure having a field exciting winding', a shaft, a hub mounted on said shaft, a plurality of circumferentially spaced spokes carried hy said hub, and an annular rim associated with said eld structure and having a plurality of outwardly extending radial passages fomed therein having an opening at each end thereof and communicating with the outer peripheral surface oi said annular rim intermediate the sides thereof, said spolres being slidably fitted in said outwardly extending passages.

1. A brake .wheel including an annular rim member having outwardly extending ventilating passages therein intermediate the sides of said annular member with openings at each end thereof, a hub, and means for concentrically mounting said rim on said hub and for providing free radial expansion of said rim with respect to said hub, said rim being radially spaced from fsaid said rim for mounting said rim on said hub and ends thereof with said outwardly extending passages.

9. A brake wheel including an annular rim member having outwardly extending Ventilating passages formed therein having openings at each end thereof and communicating with the outer peripheral surface of saidannular member intermediate the sides thereof, a hub, and means carried by said hub for mounting said rim thereon and for providing free radial expansion of 4said rim with respect to said hub.

10. A brake wheel including an annular rim having outwardly extending Ventilating passages formed therein having an opening at each end thereof and communicating with the outer peripheral surface of said annular rim intermediate the sides thereof, a hub, and -means carried by said rim for concentrically mounting said rim on said hub and for providing free radial expansion of said rim with respect to said hub.

11. A brake wheel including electrically conductive annular members axially spaced apart, a hub having circumferentially spaced openings therein, and means including spokes joining said annular members together and arranged in said openings in said hub for mounting said annular members in radially spaced lrelation on said hub and for providing free radial expansion of said vannular members `with respect to said hub.

12. A brake whelrincluding a hub comprising a slotted disk and a cylindrical axially extending member, a pair of electrically conductive annular members axially spaced apart, and means in` cluding spokes in thermally conductive relation with said annular members and arranged in the slots in said slotted disk for mounting said annular members in )radially spaced relation on said hub and for providing fr'ee radial expansion of said annular members with respect to said hub.

v13. A brake wheel including an annular rim having outwardly' extending passages lformed therein having an opening at each end thereof and communicating with/the outer peripheral surface of said annular rim intermediate the sides thereof, and a hub having circumferentially spaced spokes carried thereon, said spokes being slidably tted in said outwardly-extending passages.

14. A brake Awheel including an annular rim having outwardly extending passages formed therein having an opening at each end thereof and communicating with the outer peripheral surface of said annular rim intermediate the sides thereof, and a hub having circumferentially spaced spokes carried thereon, said spokes being slidably fitted in a plurality of said outwardly HUBERT W. GOULDTHORPE. 

